Scarf osteotomy for correction of painful hallux valgus is an effective technique, giving a predictable correction of the deformity. However, some patients remain less than fully satisfied, despite normalisation of the usual radiographic parameters. This study examines whether lateral soft tissue release can cause late splaying of the forefoot.

A series of 32 feet in 29 consecutive patients in a single centre, operated on by a single surgeon, over a 12 month period were studied. After pre-operative weight-bearing x-rays and consenting, a standardised ‘Barouk-technique’ Scarf procedure was undertaken with on-table assessment for lateral soft tissue release and phalangeal varisation. Post-operatively, patients were kept heel weight-bearing without cast for 6 weeks, with use of a fabric splint after removal of bandages at 2 weeks.

HVA and IMA were measured pre-operatively, at 6 weeks, and at 6-12 month follow-up. Distance from the mid-points of the 1st to the 5th metatarsal heads and distance from lateral sesamoid to 2nd metatarsal shaft were also recorded by blinded observers. AOFAS Foot Scores were collected prospectively. Student's t-test for single-tailed paired data was applied and p-values calculated. There were 22 female and 10 male feet; in patients aged 27 to 74 (mean 58).

Average HVA improved from 34° to 17° and was maintained at 16°. IMA improved from 14° to 7°, but then increased significantly to 10°. Overall inter-metatarsal width reduced from 76mm to 65mm but then significantly increased to 71mm. Sesamoid distance was also reduced and later increased, but not significantly. Mean foot scores improved from 52 to 85 at late follow-up. Complication rate was low.

Late widening occurred more in those feet with bigger original HVA, which were likely to have had more extensive soft tissue release (deep inter-metatarsal ligament). We recommend cautious release; and pre-operatively counselling specifically regarding eventual overall foot-width.